Project Information
RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence
Start Date:
End Date:
The Siple Coast in West Antarctica has undergone significant glacier changes over the last millenium. Several ice streams--rapidly moving streams of ice bordered by slow-moving ice--exist in this region that feeds into the Ross Ice Shelf. A long-term slowdown of Whillans Ice Stream appears to be occurring, and this is affecting the zone between the Whillans and Mercer Ice Streams. However, the consistency of this slowdown and resulting changes to the shear margin between the two ice streams are unknown. Shear zone stability represents a potentially critical control on mass balance of ice sheets, especially in regions of fast ice flow where basal shear stress is minimal. This project is therefore focused on understanding the spatial and temporal change of ice flow kinematics, shear margin structure, and shear margin location between Whillans and Mercer Ice Streams. A collateral benefit of and driver for this as a RAPID project is to test a method for assessing where crevassing will develop in this zone of steep velocity gradients. Such a method may benefit not only near-term field-project planning in the 2018-19 field season, but also planning for future fieldwork and traverses.

The team will use velocity estimates derived from available remote sensing datasets to determine transient velocity patterns and shifts in the shear-zone location over the last 20 years. This velocity time series will be incorporated into a large-scale ice-sheet model to estimate ice-sheet susceptibility to changing boundary conditions over the next century based on likely regional ice-flux scenarios. This approach is an extension of recent work conducted by the team that shows promise for predicting areas of changing high strain rates indicative of an active glacier shear margin. The ultimate objectives are to characterize the flow field of merging ice streams over time and investigate lateral boundary migration. This will provide a better understanding of shear-margin control on ice-shelf and up-glacier stability.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Person Role
Campbell, Seth Investigator and contact
Koons, Peter Co-Investigator
Kaluzienski, Lynn Technical Contact
Courville, Zoe Other
Antarctic Glaciology Award # 1842021
Polar Special Initiatives Award # 1842021
AMD - DIF Record(s)
Data Management Plan
None in the Database
Product Level:
1 (processed data)
Repository Title (link) Format(s) Status
USAP-DC 2017 GPR Observations of the Whillans and Mercer Ice Streams ASCII exists
USAP-DC Whillans and Mercer Shear Margin Ice Flow simulation in ISSM ASCII exists
Platforms and Instruments

This project has been viewed 12 times since May 2019 (based on unique date-IP combinations)